The story doesn't end here, though. All is well with Snell's Law through the centuries,
and it keeps on governing every little refraction in the world; glasses,
microscopes, radars etc.

Until now

In the latest issue of Science, scientists from the UCLASan Diego
reports to having created a material with a negative index of refraction.
This means that the material basically reverses the meaning of Snell's Law. When
tested with microwaves of similar frequencies being used in police
radars - hint, hint - the reflected microwaves went in the opposite
direction of that predicted by Snell's Law. Now, if we only could figure out
a use for this outside of the laboratories...

Reference: ne.se, britannica, Scientific American

So far no-one has mentioned this neat rule of thumb: when light passes into a denser medium its speed decreases and it "bends" toward the normal. Conversely, when light gains speed it bends away from the normal.